Functional composite fiber and preparation thereof and spinneret for preparing the same

ABSTRACT

A functional composite fiber and preparation thereof, and a spinneret for preparing the same. The functional composite fiber comprises a plurality of the T-lobes connected with each other at their bases, wherein the caps of the T-lobes contain a component, and their bases T-lobes contain the component and an additive. The additive is not exposed on the surface of the fiber thereby preventing post-manufacturing abrasion of the spinning machine.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a functional composite fiber. Moreparticularly, the present invention relates to a composite fibercontaining a functional component not exposed on the surface thereof,thereby avoiding abrasion of the spinning machine duringpost-manufacturing.

2. Description of the Related Arts

Currently, composite fibers contain T-shaped lobes and open channelsformed thereon, provide the ability to wick perspiration away from thehuman body. As multi-functional fibers have become a trend, blendinginorganic chemicals such as anti-ultraviolet (anti-UV) agent, far-intrared (far-IR) agent, or anti-bacterial & mildew-retarding agents intomulti-function fiber groups has become widespread. For example, U.S.Pat. No. 5,057,368 discloses a trilobal or quadrilobal fiber composed ofone polymer or a mixture of various polymers; U.S. Pat. No. 6,093,491discloses a thermoplastic fiber comprising a fiber with one or moreinternal lengthwise open channels and a durable hydrophilic surfacemodifier associated with the channels; and U.S. Pat. No. 5,707,735discloses a conjugate multilobal fiber comprising at least two polymersarranged with at least one polymer occupying a portion of the fiber andat least one other polymer having a lower melting point than the firstportion polymer occupying an outer portion of the fiber. Fibercontaining inorganic chemicals, however, may abrade the yarn guide,tension sensor, or the PU disc during post-manufacturing processes andresult in broken filaments or skittery dyeing. Therefore, improvedcomposite fibers and the manufacturing method thereof is required.

SUMMARY OF THE INVENTION

It is a primary object of the present invention to provide a functionalcomposite fiber with an unexposed inorganic chemical which does notcontact the yarn guide or PU disc, preventing post-manufacturingabrasion of these elements. The abrasion of these elements may affectthe quality of fiber products and also incur extraneous expenses.

Accordingly, the present invention provides a functional composite fibercomprising a plurality of the T-lobes connected to each other at theirbases. The caps of the T-lobes contain a component and the bases of theT-lobes contain the component and an additive. The additive is notexposed on the surface of the fiber; therefore, the yarn guide and PUdisc are not abraded by the additive. The quality of fiber products canbe maintained, and extraneous costs for maintaining the abraded yarnguide and PU disc can be prevented. The fiber of the present inventioncan be a porous hollow fiber with polygonal cross-sections while thecaps of the T-lobes are connected to each other or a non-hollow fiberwith multilateral cross-section while the caps of the T-lobes are notconnected, for use in autumn/winter or spring/summer garmentsrespectively.

In another aspect of the present invention, a spinneret is provided forthe manufacture of the previously described fiber. The spinneretcomprises a plurality of rectangular first exits extending outward toform an equilateral polygon, and a plurality of rectangular second exitsradially arranged from the mass center of the equilateral polygon toeach side of equilateral polygon. The length of the first exits can belonger or shorter than that of the second exits to manufacture theporous hollow fiber with polygonal cross-section or the non-hollow fiberwith multilateral cross-section respectively.

In another aspect of the present invention, a manufacturing method for afunctional composite fiber is provided. The method comprises producingthe functional composite fiber by the above mentioned spinneret. Thefiber is composed of a first component and a second component, and thefirst component is extruded from the first exit while the secondcomponent is extruded from the second exit. When the length of the firstexit is longer than that of the second exit and the gap between adjacentfirst exits is less than 0.1 mm, the porous hollow fiber with polygonalcross-section can be obtained. When the length of the first exit isshorter than that of the second exit, the non-hollow fiber withmultilateral cross-section can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood and furtheradvantages will become apparent when reference is made to the followingdescription of the invention and the accompanying drawings in which:

FIGS. 1A-1B are cross-sections showing the fiber with single componentof the prior art. FIG. 1A represents the cross-section of 3T fibers;FIG. 1B represents the cross-section of tri-porous hollow fibers.

FIG. 2 is a lateral view showing the spinning machine for the functionalcomposite fiber of the present invention.

FIG. 3A-3B are diagrams showing the spinnerets for the functionalcomposite fiber of the present invention. FIG. 3A shows the spinneretfor the functional composite fiber in example 1; FIG. 3B shows thespinneret for the functional composite fiber in example 2.

FIG. 4 is a cross-section showing the functional composite fiber inexample 1.

FIG. 5 is a cross-section showing the functional composite fiber inexample 2.

FIG. 6 is a diagram showing the comparison of drying speed between thefunctional composite fiber in example 1 of the invention and the fiberof prior art.

FIG. 7 is a diagram showing the comparison of heat retention between thefunctional composite fiber in example 2 of the invention and the fiberof prior art.

FIG. 8A-8D are diagrams showing the abrasion of the yarn guide. FIG. 8Ashows the yarn guide after 7-day (168 hours) spinning with the spinneretof the present invention; FIG. 8B shows the yarn guide after 1-day (24hours) spinning by a regular spinneret with polyester fiber containinginorganic chemicals; FIGS. 8C and 8D are enlarged photos of FIG. 8D indifferent views.

DETAILED DESCRIPTION OF THE INVENTION

Without intending to limit it in any manner, the present invention willbe further illustrated by the following description.

The functional composite fiber of the present invention features atleast two T-lobes, preferably three T-lobes, connected at their bases.The caps of the T-lobes contain a first component and the bases of theT-lobes contain a second component including the first component and anadditive. When the fiber is a porous hollow fiber with polygonalcross-section, the cap of each T-lobe is connected to another T-lobe orto a non-hollow fiber with multilateral cross-section when the cap ofeach T-lobe is not connected to another cap. The component includes, butis not limited to, polyester, nylon, polyolefin, poly(acrylonitrile)(PAN), or cellulose; the polyester includes polyethylene terephthalate(PET), polybutylene terephthalate (PBT), or polypropylene terephthalate(PPT); nylon includes N6 or N66; polyolefin include polypropylene (PP)or polyethylene (PE). Preferably, the component is PET. The additivesinclude, but are not limited to, anti-bacterial & mildew-retardingagents, anti-conductive agent, anti-UV agent, or far-IR agent.

The manufacturing method of the present invention is performed by anintubated composite spinning machine 5 as shown in FIG. 2 and spinneret6 as shown in FIGS. 3A and 3B. The intubated composite spinning machine5 has an inner tube 2 and an outer tube 1. The spinneret of the presentinvention includes a plurality of square first exits (3 a and 3 b)extending outward to form an equilateral polygon, and a plurality ofsquare second exits 4 radially arranged from the mass center of theequilateral polygon to each side of equilateral polygon. Typically thereare three square first exits which form an equilateral triangle as shownin FIGS. 3A and 3B. In addition, the adjacent first and second exitsform a right angle. The above mentioned second component, a meltingpolymer containing an abrasive inorganic chemical, is introduced intothe inner tube 2 of the composite spinning machine 5 and extruded fromthe second exits 4 of spinneret 6 to form the bases of the fibers. Thefirst component is introduced into the outer tube 1 of compositespinning machine 5 and extruded from the first exits (3 a and 3 b) toform the caps of the fibers. The inorganic additive of the obtainedfiber does not contact with the yarn guide and the PU disc, thuspreventing abrasion during post-manufacturing and maintaining fiberproduct quality. In addition, as shown in FIGS. 3A and 3B, thenon-hollow fiber with multilateral cross-section can be obtained usingthe spinneret 6 of FIG. 3A, in which the first exits 3 a are shorterthan the second exits 4; or the porous hollow fiber with polygonalcross-section can be obtained using the spinneret 6 of FIG. 3B, in whichthe first exits 3 b is longer than the second exits 4 and the twoadjacent first exits 3 b have a gap 7. The non-hollow fiber withmultilateral cross-section and the porous hollow fiber with polygonalcross-section can be applied in spring/summer and autumn/winter garmentsrespectively.

Practical examples are described herein.

Control Manufacture of the Trilobal Non-Hollow and Tri-Porous HollowFibers with Single Component

The trilobal non-hollow fiber as shown in FIG. 1A and the tri-poroushollow fiber as shown in FIG. 1B were produced by the method known bythose skilled in the art using a one-tube spinning machine, a regulartrilobal spinneret, and polyethylene terephthalate (PET) as spinningmaterial. The power for FIGS. 1A and 1B is 12.5×20.

EXAMPLE 1 Manufacture for the Non-Hollow Composite Fiber withMultilateral Cross-Section of the Invention

The non-hollow composite fiber with multilateral cross-section wasprepared using the spinning machine as shown in FIG. 2 and the spinneretas shown in FIG. 3A. The spinning materials are polyethyleneterephthalate (PET) extruded from the second exit and PET supplementedwith anti-UV agent, for example, 2.3% TiO₂, extruded from the firstexit. The cross-section of resulting fibers is shown in FIG. 4 with apower of 12.5×20. The tenacity of the fiber is over 3.0 g/den, thefineness is 1.5˜3.0 dpf, and the elongation is 20˜30%.

EXAMPLE 2 Manufacture of the Porous Hollow Composite Fiber withPolygonal Cross-Section of the Invention

The porous hollow composite fiber with polygonal cross-section wasprepared using the spinning machine as shown in FIG. 2 and the spinneretas shown in FIG. 3B. The spinning materials are PET extruded from thesecond exit and PET supplemented with far-IR agent, for example, 0.3˜1%ZnO₂, extruded from the first exit. The cross-section of resultingfibers is shown in FIG. 5 with a power of 12.5×20. The tenacity of thefiber is over 3.5 g/den, the fineness is 1.5˜3.0 dpf, and the elongationis 20˜30%.

EXAMPLE 3 Properties of the Non-Hollow Composite Fiber with MultilateralCross-Section in the Present Invention

Drying speed assay: the sample of 10×10 cm² is placed in a constanttemperature (23° C.) and humidity (65% RH) for 24 hours. The sample isthen placed on a laboratory balance, and an amount of water (W₁) isdropped into the sample from 1 cm height. The amount of residual water(W₂) is measured after 12 min, and the evaporation rate is calculatedas:

-   -   Evaporation rate (%)=(W1-W2)/W1×100%

The results are shown as FIG. 6. The comparison of drying speed in thefiber of the present invention, cotton, and general polyester shows thatthe drying speed of the fiber in the present invention (50%) is betterthan cotton (about 30%) and general polyester (less than 10%).

EXAMPLE 4 Properties of the Porous Hollow Composite Fiber with PolygonalCross-Section in the Present Invention

Temperature change assay: the measurement is performed by an AGEMAThermalvision 900 heat conductivity sensor using a 500 W halogen lamp asa heat source. The sample is placed 100 cm under the heat source for 10min. The temperature differences are measured before and after exposureto the heat source.

The results are shown as FIG. 7. The temperature comparison of the fiberin the present invention before and after exposure to the heat sourcereveals that it has excellent heat-insulation ability.

EXAMPLE 5 Abrasion Test for the Fiber of the Present Invention

Using a 36-pore spinneret under a yield of 0.99 g long fiber/min/poreand a spinning speed of 2800 m/min, the abrasion of yarn guide wasperformed.

For the manufacture of general polyester fiber supplemented withinorganic additives, using the conventional spinneret, the yarn guidewas abraded after one day (24 hours) as shown in FIG. 8B-8D; FIGS. 8Cand 8D are photographs showing the amplified abrasion site of FIG. 8B indifferent views. Using the spinneret of the present invention, the yarnguide remained intact after 7-days (168 hours) of spinning.

The manufacture of functional composite fiber in the present inventionincorporates a specially designed spinneret which prevents thefunctional component from being exposed on the surface of the fiber,thus preventing abrasion to the yarn guide and PU disc and extraneouscost of fiber. In addition, the size of the first and second exits ofthe spinneret can be adjusted to form porous hollow fibers withpolygonal cross-section or non-hollow fibers with multilateralcross-section. Fabric comprising non-hollow composite fiber withmultilateral cross-section features water diffusion and wickingproperties; therefore, the fabric does not stick to the skin, andmaintains a crisp appearance and provides comfort due to its capillaryaction. In addition, the inner additive of anti-UV agent features washresistance and protects the skin from UV radiation. Moreover, fabriccomprising porous hollow composite fiber with polygonal cross-section islight weight and provides heat insulation by preventing air convection.

While the invention has been particularly shown and described with thereference to the preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade without departing from the spirit and scope of the invention.

1.-6. (canceled)
 7. A spinneret for the manufacture of a functionalcomposite fiber having a plurality of the T-lobes connected at theirbases, and the caps of the T-lobes contain a component and their basescontain the component and an additive, the spinneret comprising: aplurality of rectangular first exits extending outward to form anequilateral polygon, and a plurality of rectangular second exitsradially arranged from the mass center of the equilateral polygon toeach side of equilateral polygon.
 8. The spinneret as claimed in claim7, wherein the adjacent first and second exits form a right angle. 9.The spinneret as claimed in claim 7, wherein the first exit is longerthan the second exit.
 10. The spinneret as claimed in claim 7, whereinthe first exit is shorter than the second exit.
 11. The spinneret asclaimed in claim 7, wherein the equilateral polygon is an equilateraltriangle. 12.-20. (canceled)